1. Field of the Present Disclosure
This disclosure relates generally to internal combustion engine fuel delivery systems and methods. More specifically, this invention relates to a system and method for providing a more efficient use of gasoline for operating an internal combustion engine by vaporizing fuel prior to injection into engine cylinders.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Grice, U.S. Pat. No. 5,596,973 discloses a fuel expander which is placed in-line in a fuel supply system for an engine that has a heat exchange means, which receives heat from an engine component, such as a radiator hose, and transfers the heat to the fuel supply system prior to the fuel reaching the engine. The fuel expander has a mesh screen near the entrance to the fuel expander. Auxiliary heating means may be used with the device.
Gray, U.S. Pat. No. 6,186,126 discloses an automotive power plant that includes an internal combustion engine and a heat exchanger for vaporizing fuel to the internal combustion engine utilizing heat from the combustion exhaust gas. The vaporized fuel may be fed to a combustion cylinder containing the compressed gas produced by a compression stroke. Alternatively, the vaporized gas may be fed to a dedicated expander for extracting work therefrom and then fed to the internal combustion engine.
Covey, U.S. Pat. No. 4,883,616 discloses a vaporizer unit having an enclosed casing including a plurality of tubes therein, defining a fuel passage therethrough, including the tubes. The tubes have coiled wire screen therein. An auxiliary carburetor is positioned at the inlet end of the fuel passage, and an outlet passage leads to the main carburetor of the automobile. The casing also defines an exhaust passage therethrough, transversely of the fuel passage, providing heat transfer between the exhaust gases and the tubes. The temperature of the resulting vaporized fuel is sensed for varying the flow of the exhaust gases and thereby controlling the temperature of the vaporized fuel, which is maintained between 250 and 260 degrees C. An electric crystal is used for breaking down the heavy ends of the fuel. The rate of flow of air to the main carburetor is varied for correspondingly varying the rate of intake of vaporized fuel from the vaporizer unit. Automatic and manual controls are both utilized selectively, each without interfering with the other.
Hoffman, U.S. Pat. No. 4,480,622 discloses a fuel vaporizer for an internal combustion engine comprising an elongate vaporizer chamber having one end connected to a source of air and atomized liquid fuel, and the other end connected with a throttle valve for controlling a flow of vaporized fuel to the cylinders of an engine. A passage extends longitudinally of the chamber for flow of hot exhaust gasses in heat exchange relationship with the air and atomized fuel mixture to vaporize the fuel to a heated, dry vaporous state. The atomized fuel and air mixture flows through a plurality of passages extending through a body of material having high thermal conductivity.
Tsoi-Hei Ma, GB 2312923 discloses a heat exchanger arranged upstream of fuel injectors, for transferring heat from a heating fluid to the fuel that is to be injected, the temperature of the fluid is constantly maintained at a value not exceeding the boiling point of the fuel at the prevailing pressure of the fuel in the heat exchanger. The fluid may be a liquid that is heated electrically and the fluid circuit may include an insulated reservoir. The fluid may be exhaust gases or engine coolant from two sources at temperatures above and the below the temperature to be maintained. A valve may control the flows from the two sources in response to a thermostat in the mixed flows. The heating temperature may be up to 50 degrees Celsius for port injection, 50 to 100 degrees Celsius for direct fuel injection and 200 to 260 degrees Celsius for diesel injection.
Gupta et al., US 2006/0037589 discloses an internal combustion engine fuel system having a membrane separator for separating a primary fuel into a high octane fuel and a low octane fuel, and wherein the primary fuel is heated for separation in the membrane separator. A heat pipe having an evaporator section is positioned in a heat exchange relationship with exhaust gas from the internal combustion engine. A heat output area is in a further heat exchange relationship with a primary fuel as it is fed into the separator whereby the primary fuel is heated. In one embodiment a variable conductance heat pipe has a top operating temperature not greater than about 160 degrees Celsuis.
Pugachev et al, U.S. Pat. No. 5,327,874 discloses a fuel feed system for an internal combustion wherein a rich fuel-air mixture is fed as a main flow to decompose liquid fuel and convert it into a gas. A technical aim of the present invention consists in an increased fuel economy of the engine, reduced toxicity of exhaust gases, and use of a cheaper low-octane fuel. A method for preparing fuel-air mixture consists in mixing a heated, over rich fuel-air mixture with another flow of fuel-air mixture, by passing it through a promoter heated above the mixture ignition temperature, thus providing repeated contact of the flow with the promoter surface.
Stone, U.S. Pat. No. 6,557,535 discloses a system and method for transferring heat from the exhaust of an internal combustion engine to a fuel container storing compressed gas fuel, using a gaseous heat transfer medium. The heat transferred to the fuel container assists expansion and/or vaporization of the compressed gas fuel. The expanded and/or vaporized compressed gas fuel may be delivered to the internal combustion engine for use by the engine.
Covey, U.S. Pat. No. 5,291,870 discloses a system for providing an air-fuel vapor mixture to an engine for improving completeness of combustion and also reducing emissions. The system includes a vaporizer within which a series of baffles are disposed such that air and fuel pass along a tortuous passageway defined within the vaporizer. Exhaust gases provide heat to the vaporizer, and as air and fuel pass along the passageway of the vaporizer, a homogenous air-fuel vapor mixture is produced, with the homogenous mixture exiting the vaporizer being supplied to the engine by way of an adapter plate assembly. When used with a carburetor, the adapter plate is disposed between the carburetor and the engine.
Glass, U.S. Pat. No. 4,515,135 discloses a hot fuel gas generator for an internal combustion engine of the piston type that vaporizes liquid fuel such as gasoline and delivers the same to the engine through a control valve which is responsive in operation to accelerator linkage controlling the internal combustion engine's operation. The hot fuel gas generator uses exhaust gases as a heat source and communicates with an adaptor block mounted on the inlet manifold of the internal combustion engine. A conventional carburetor may be carried on the adaptor block along with a conventional air cleaner as known in the art. The hot fuel gas generator separately makes superheated steam from a controlled amount of water and mixes the steam with the gasified fuel in a mixing chamber which is enclosed in a hollow body member through which hot exhaust gases from the equipped internal combustion engine are directed prior to their delivery to an exhaust system.
Chu, U.S. Pat. No. 6,868,839 discloses a vaporized fuel injection system for a combustion engine that includes a fuel vaporization chamber and a two-way valve. The fuel vaporization chamber has a chamber input and a chamber output, and is connected with a fuel source via the chamber input. The fuel vaporization chamber is for vaporizing fuel input to the chamber input and outputting vaporized fuel to the chamber output. The two-way valve has first and second valve inputs and a valve output. The first valve input is connected to the chamber output, and the second valve input is connected to the fuel source. The two-way valve is switchable to allow fuel to flow from only one of the first or second valve inputs to the valve output.
The related art described above discloses fuel systems using heat from exhaust or coolant systems to vaporize fuel in order to improve engine operating efficiency and reduce unwanted components of exhaust gases. However, the prior art fails to disclose the present improved and novel system for maintaining operation during both cold starts and periods of excessive heat absorption. The present disclosure distinguishes over the prior art providing heretofore unknown advantages as described in the following summary and detailed description.